The present invention relates to ratchet wrenches such as socket wrenches, and in particular to ratchet wrenches with improved tool release mechanisms that resist inadvertent operation and to ratchet wrenches with improved means for holding the ratchet wheel in engagement with the pawl.
U.S. Pat. No. 3,208,318 discloses an effective tool release mechanism for tools such as sockets. In the disclosed system a control rod is axially slidable in a drive stud of the wrench, and the control rod defines a ramp surface on which a ball rides. A spring biases the control rod outwardly to a rest position, in which the ball positively engages an accommodating recess in a tool such as a socket. When it is desired to release the socket from the drive stud, the control rod is depressed against the biasing force of the spring, thereby allowing the ball to move down the ramp to a position that allows removal of the socket.
The tool release mechanism of the above-identified patent has been found to be reliable and effective in use. However, the possibility exists that under some circumstances a user may inadvertently depress the control rod while using the wrench. This may happen for example if the head of the wrench is placed in the palm of the user's hand. In this case the palm of the user's hand can come into contact with the upper end of the control rod, and can inadvertently depress the control rod while the wrench is in use, thereby inadvertently releasing the socket. One object of certain embodiments described below is to overcome this potential drawback of the prior art.
Roberts U.S. Pat. No. 4,420,995 discloses a tool release mechanism for tools such as sockets. In the disclosed ratchet mechanism a ratchet wheel is provided with an annular raised boss on the side of the ratchet wheel opposite the drive stud, and this boss fits within a recess in the head of the wrench. The boss resists forces tending to decenter the ratchet wheel with respect to its axis of rotation.